diff --git a/Flow.Launcher.Core/Resource/InternationalizationManager.cs b/Flow.Launcher.Core/Resource/InternationalizationManager.cs
index 79736edc3..5d718466c 100644
--- a/Flow.Launcher.Core/Resource/InternationalizationManager.cs
+++ b/Flow.Launcher.Core/Resource/InternationalizationManager.cs
@@ -1,7 +1,9 @@
-using CommunityToolkit.Mvvm.DependencyInjection;
+using System;
+using CommunityToolkit.Mvvm.DependencyInjection;
 
 namespace Flow.Launcher.Core.Resource
 {
+    [Obsolete("InternationalizationManager.Instance is obsolete. Use Ioc.Default.GetRequiredService<Internationalization>() instead.")]
     public static class InternationalizationManager
     {
         public static Internationalization Instance
diff --git a/Flow.Launcher.Core/Resource/ThemeManager.cs b/Flow.Launcher.Core/Resource/ThemeManager.cs
index 68cd90a7e..3cbe8319a 100644
--- a/Flow.Launcher.Core/Resource/ThemeManager.cs
+++ b/Flow.Launcher.Core/Resource/ThemeManager.cs
@@ -1,7 +1,9 @@
-using CommunityToolkit.Mvvm.DependencyInjection;
+using System;
+using CommunityToolkit.Mvvm.DependencyInjection;
 
 namespace Flow.Launcher.Core.Resource
 {
+    [Obsolete("ThemeManager.Instance is obsolete. Use Ioc.Default.GetRequiredService<Theme>() instead.")]
     public class ThemeManager
     {
         public static Theme Instance